Prime Minister David Cameron's call for a new deal to keep Britain inside the European Union won little support Wednesday as fellow leaders, mindful of the potential fallout, warned against "a la carte" union.

"We can't have Europe a la carte," French Foreign Minister Laurent Fabius said. "Imagine the EU was a football club: Once you've joined up and you're in this club, you can't then say you want to play rugby."

Fabius's boss, French President Francois Hollande, said it was not possible to negotiate Britain's membership terms.

"The United Kingdom can perfectly well decide in a referendum to stay in or leave the European Union, that's a decision for the rulers of the country and the British people themselves," Hollande told reporters.

"But what I say on behalf of France, and also as a European, is that it is not possible to negotiate Europe for this referendum."

Though EU officials in Brussels politely welcomed Cameron's declared willingness to fight to keep London in the bloc after months of talk of "Brixit", or British EU exit, even London's traditional allies in northern Europe appeared to give Cameron the cold shoulder.

Saying she hoped Britain would remain a part of the bloc, Danish Prime Minister Helle Thorning-Schmidt said "we believe that Danish interests are best served by staying as close to the EU core as possible. A strong EU is in the clear interest of Denmark."

In Vienna, Austrian Chancellor Werner Faymann had harsh words for Cameron, saying he was drawing Britain into isolation due to his inability to compromise.

"This is not serious politics, it is not in the interests of the citizens or the economy of Europe, nor that of Britain's citizens or its economy."

Mark Rutte, prime minister of the Netherlands, where Cameron had originally been due to give his speech before the Algerian hostage crisis erupted, welcomed Cameron's call for EU reform, something many Dutch people feel is sorely needed.

"That debate is good. What wouldn't be good is if the outcome is that the United Kingdom leaves the EU. That's bad for the United Kingdom and bad for Europe," he said.

In his much-publicised speech, Cameron vowed that if he was re-elected he would renegotiate the terms of London's notoriously troubled EU membership, taking and picking what the bloc has best to offer.

Once a new deal were won, increasingly eurosceptic Britons would be asked to vote by late 2017 on whether to remain in the bloc.

Apparently extending a hand to Cameron, Chancellor Angela Merkel said Germany was ready to discuss Britain's "wishes" on the EU, but in almost the same breath warned that caving in to one country would mean caving in to another.

"We are of course ready also to talk about British wishes but one must keep in mind that other countries also have other wishes and we must in the end always find a compromise," she said.

Italian Prime Minister Mario Monti said he believed British citizens would vote to stay in the EU, adding the bloc desperately needed "willing Europeans."

"It is unthinkable for London to consider a future outside of Europe in a moment in which the European Union's role is ever more central," added Italian Foreign Minister Giulio Terzi.

Picking and choosing the bits and pieces of EU legislation that seemed most attractive to a nation simply could not work and would set a dangerous precedent, warned European Parliament President Martin Schulz.

"I suspect that Prime Minister Cameron with his referendum announcement is playing a dangerous game for tactical, domestic reasons," he said.

"It could lead to piecemeal legislation, disintegration and potentially the breaking of the Union."

Brussels officials meanwhile sought comfort in the fact that a British decision lay years away and a spokeswoman for the executive European Commission said it "welcomes that David Cameron wants Britain to remain in the EU."

It "is very much in the EU's interest and UK's interest" that London remain "an active member" of the 27-nation bloc, spokeswoman Pia Ahrenkilde Hansen said.

"The UK brings a great deal to European integration and has helped shape Europe's policies."

Cameron's resolve to get the best for Britain will be tested at a summit next month, February 7 and 8, to reach a deal on the next long-term EU budget. The last budget summit in November flopped over a British-led bid to slice proposals for EU spending in 2014-2020.